1. Field Of The Invention
This invention relates generally to a riding toy mechanism and more specifically to a mechanism which provides a compound reciprocating motion to the rider.
2. Related Art
Riding toy mechanisms of the prior art commonly derive reciprocating motion from the regular oscillation of crank shafts, gears or pulleys operated by the user's feet or by a motor. For example, U.S. Pat. No. 3,068,000 to Hanson discloses a foot operated riding toy having a seat which has a forward end and a rearward end, both of which are mounted by offset shaft members on crank shafts to which a central crank shaft is connected by connector rods. Pedals allow the user to rotate the central crank shaft, and thereby, the forward and rearward crank shafts, thus imparting reciprocating motion to the seat member. The amplitude of the reciprocating motion imparted to the seat is determined by the length of the offset shaft members. Since this length is fixed, the motion imparted to the seat member at the point where it is connected to the offset shaft will be circular, and the vertical and horizontal or lateral components thereof have mutually dependent amplitudes. The rate at which the seat member goes through the circular reciprocation, and therefore the frequency of the vertical and horizontal reciprocation motions, will be determined by the rotational speed of the central crank shaft driven by the user's feet.
The common use of crank shafts, regular (i.e., round) gears, and reciprocating drives impart to the riding toys of the prior art a common characteristic. This is that the motion of the riding toy, as imparted to its seat member, and therefore the motion experienced by its rider, is determined by a circular path of travel, or a combination of circular paths of travel, imposed on the toy by the rotation of its driving crank, gear or pulley. When a single circular motion drives the seat member, the lateral and vertical components thereof have the same profile, i.e., are sinusoidal, and out of phase by 90 degrees. The amplitude of the vertical motion is thus dependent upon or coupled with that of the lateral motion. Both motions, and the overall motion of the drive, are described as harmonic because they derive from circular motion or components thereof.
A similar motion is seen in the hobby horse disclosed by Jensen, U.S. Pat. No. 2,473,649 in which the saddle is mounted on forward and rearward support members which are mounted to the offset portions of forward and rearward crank shafts. A pedal driven sprocket assembly drives the crank shafts by a drive chain. As with the device disclosed by Hanson, Jensen's hobby horse moves in a circular pattern in which the amplitude and frequency of the lateral and vertical reciprocating motions are the same, but 90 degrees out of phase.
British Patent Specification 742,295 to Berry discloses a dual drive mechanical horse mechanism in which the forward end is pivotably mounted to a pair of motor-driven crank-mounted support poles through a linkage which allows the horse to rock to-and-fro. At the rear end, the horse is mounted to a second motor-driven crank which imposes a circular motion on the rear end of the horse, with the associated, mutually coupled lateral and vertical reciprocating motions. The configuration of the support poles causes vertical reciprocating motion to be imposed upon the front end of the horse with a minimum of associated lateral motion. While the motion of this riding toy is slightly more complex than that of the device disclosed by Hanson and Jensen, it still suffers from the same principal limitation, i.e., that the lateral and vertical components of motion derive from purely circular driving mechanisms and are therefore mutually dependent. In this case, the amplitude of the vertical reciprocating motion is the sum of the vertical components of two circular motions, and is in this sense a harmonic, if not sinusoidal, motion.
The prior art includes a variation on the previously discussed reciprocating motion in the disclosure of Goodrich, U.S. Pat. No. 1,647,616. Goodrich provides a saddle member which is pivotably mounted to a support. An extension bar extends forwardly from the saddle member and is attached to a reciprocating rod and pulley assembly. The saddle member may therefore rock to-and-fro in response to the reciprocation assembly, but, because it is pivotably mounted, cannot provide vertical motion. However, Goodrich provides oblique motion through the use of linkage 102 connected to the saddle member by universal joint 101 and to the pivot shaft 21. This linkage provides a sideward motion coordinated with the rocking of the saddle member to simulate the swagger of the rear end of a horse. The swagger motion and the rocking motion in the device disclosed by Goodrich are supplied by different motors, so the respective frequencies thereof are mutually independent, but they are both sinusoidal.
U.S. Pat. No. 710,218 to J. Seng discloses a hobby horse which is pivotably mounted to a stationary support. The horse is also attached via a pivotable linkage to a crank shaft which is driven by pedals operated by the user to produce a to-and-fro rocking motion. In this case, only one degree of freedom, i.e., rotation about the pivot mounting, is allowed.
Some riding mechanisms in the prior art are not mounted to stationary supports, and are designed to advance in a forward motion as the user operates the device. For example, U.S. Pat. No. 1,819,029 to King et al discloses a pedal-driven mechanical toy horse including a drive gear which causes the legs of the device to extend and retract. The legs are equipped with wheels which are movable between two positions, one in which the wheel turns easily while the leg is extending forward and one in which the wheel is braked, while the leg is retracting. In this way, the mechanism advances as the user operates the pedals.
U.S. Pat. No. 2,237,605 to Maypole discloses a moving mechanical horse on which the legs are all provided with wheels having clutch means, and the rear legs extend and retract in response to the user's application of pressure to a stirrup mechanism. By coordinating operation of the respective clutch mechanisms of the front and rear wheels the horse advances in response to the user's operation. In such moving mechanical horses, the clutch mechanisms in the wheels operate to prevent lateral reciprocation; simple straightforward motion is attained instead. Slight vertical oscillation is provided, but the amplitude thereof is determined by the degree of extension and retraction of the legs of the device.